Hebrews 23 To the General Assembly of the Firstborn

To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,

"To the general assembly and church of the firstborn" (Hebrews 12:23 KJV) may actually be considered as dual in nature. As Head of His Church, Jesus Christ "is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all things He might have the preeminence" (Colossians 1:18 KJV), but His people of the true Church, who will be in the first resurrection at the time of Christ's return (see the Fact Finder question below to understand why and when there will be two resurrections, and why the first resurrection will be to spirit while those of the second resurrection will be back to physical life) will be the firstborn of salvation, "For as in Adam all die, even so in Christ shall all be made alive. But every man in his own order: Christ the first fruits; afterward they that are Christ's at his coming." (1 Corinthians 15:22-23 KJV).